• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.842-846
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• 2001

Our company produces boilers for industrial usages or power plants. The aim of this study is to investigate the flame structure, heat transfer to evaporator tube wall and NOx emission in the furnaces. Also we are to derive correct FEGT(Furnace Exit Gas Temperature) characteristic curve. When we design furnace and superheater, economizer etc. FEGT characteristic curve is very important factor for optimum design. We calculated turbulent reacting flow, heat transfer and NOx emission in furnace by using numerical modeling with the help of commercial code. Three dimensional steady state calculation is done. k-e turbulence model and equilibrium chemistry combustion model with $\beta-probability$ density function is used. To calculate radiation heat transfer discrete ordinates model is used. And we measured FEGT at several operating plants. Measurement is done by R-type thermocouple. Radiation shield is attached to the thermocouple to prevent radiation effect. Measured and calculated results show good agreement. And we could understand the flame structure and NOx formation positions in each furnaces.

• 열처리공학회지
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• 제31권5호
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• pp.231-236
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• 2018

The purpose of this study was to investigate the microstructural characteristics and hardness distribution of AZ91 magnesium alloy furnace-cooled to room temperature after solution treatment, and to compare the results with those of as-cast condition. The as-cast alloy showed a partially divorced eutectic ${\beta}(Mg_{17}Al_{12})$ phase and discontinuous precipitates (DPs) with a lamellar morphology, while only DPs were observed in the furnace-cooled alloy. The DPs in the furnace-cooled AZ91 alloy had various apparent interlamellar spacings, which would be ascribed to the different transformation temperatures during the furnace cooling. The average hardness for the furnace-cooled alloy is similar to that for the as-cast alloy. It is interesting to note that the hardness values of the furnace-cooled alloy were distributed over a narrower range than those of the as-cast alloy. This is likely to be caused by the relatively more homogeneous microstructure of the furnace-cooled alloy in comparison with the ascast one.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.210-211
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• 2014

Nowadays, as to reduce the emission volume of CO₂, blast furnace slag has been widely used to replacement of cement. Techniques about using industrial by-products has been extensively studied. For the previous study, blast furnace slag has been used with recycled fine aggregates. In thess study, considering about the different properties of blast furnace slag, as the change of blaine and chemical performances of blast furnace slag, the results of flowability and compressive strength has been analysed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.226-227
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• 2021

Various attempts are being made to reduce carbon emissions through recycling of industrial by-products in the construction materials industry to reduce carbon emissions, and cement substitutes such as blast furnace slag and fly ash are widely used. Although it is suggested that the use of industrial by-product aggregate is possible in 'Aggregate', the use case of industrial by-product aggregate is very rare in the actual field. In this study, as an industrial by-product, fine slag aggregate is used as fine aggregate among aggregates that can be used as aggregate for concrete, and coarse aggregate is used as a substitute for natural aggregate. WWe tried to suggest various ways to expand the use of industrial by-product aggregates.

• 한국산학기술학회논문지
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• 제18권8호
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• pp.338-343
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• 2017

본 논문은 이산화탄소 배출저감 및 산업폐기물을 재활용하기 위한 일환으로 산업부산물인 고로슬래그 미분말을 사용하였다. 고로슬래그 미분말은 선철의 제련 시 부산물로서 발생하는 고온 용융상태의 고로슬래그를 물로 급냉 시켜 유리화한 것으로 반응성이 높아 시멘트 및 콘크리트용 혼화재료로 다양하게 사용되고 있다. 고로슬래그 미분말을 치환한 콘크리트는 수화발열속도 저감, 온도상승 억제, 장기강도 향상, 수밀성 증대에 의한 내구성 향상 및 염화물 이온 침투억제에 의한 철근의 발청 억제 등의 다양한 효과를 기대할 수 있다. 그러나, 재령 초기 낮은 압축강도로 인해 사용량이 적은 실정이다. 따라서, 본 연구에서는 고로슬래그 미분말을 치환할 경우 낮은 압축강도를 보완하기 위해 증기양생이 초기 강도 발현에 미치는 영향을 평가하였고, 압축강도, SEM, EDS, XRD와의 관계를 분석하여 콘크리트의 압축강도 발현특성을 검토하였다. 그 결과 고로슬래그 미분말을 30% 치환한 콘크리트가 가장 우수하였으며, 이는 증기양생에 의해 고로슬래그 미분말의 피막을 파괴하여 ettringite 및 C-S-H겔 등의 수화물을 생성함으로 압축강도에 영향을 마친 것으로 판단된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.538-541
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• 1995

In steel works, reheating furnace is an essential part of a rod mill plant and it treats various types of billets continuously. Although getting an optimal setting for a single billet is simple, control setting for whole groups of billets is a difficult task. In this work, we studied a detail mathematical model and optimal control setting of reheating furnace. As the mathematical model of each billet is a partial differential equation, on-line control is almost impossible for the whole billets charged into the furnace. Therefore, we tried to provide a guideline for optimal setting value of the roof(index) temperature for the target billets which account for about 20% of the charged billets.

• Journal of Magnetics
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• 제21권2호
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• pp.204-208
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• 2016

This paper demonstrates the key parameter detection for smelting of submerged arc furnace (SAF) based on magnetic field radiation. A magnetic field radiation model for the inner structure of SAF is established based on relative theory of electromagnetic field. A simple equipment of 3D magnetic field detection system is developed by theoretical derivation and simulation. The experiments are carried out under the environment of industrial field and AC magnetic field generated by electrode currents and molten currents in the furnace is reflected outside of the furnace. The experimental results show that the key parameters of smelting including the position of electrode tip, the length of electric arc, and the liquid level of molten bath can be achieved. The computed tomography for SAF can be realized by the detection for smelting.

• 한국안전학회지
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• 제38권2호
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• pp.15-22
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• 2023

In this study, the process and the environment of a melting furnace, located in Workplace A in Chungnam Province was inspected, and the insulation resistances of electrical circuits and motors were measured, and their changes over five years (2017-2021) were analyzed. It was found that the exhaust fan, oil pumps #A and #B, and heater were installed in 2010. Their insulation resistances decreased from 2017. Specifically, the insulation resistance of Oil Pump #A decreased from 100 (㏁) in 2018 to 20(㏁) in 2021, an 80% reduction. The fast decrease in insulation resistance was due to the high temperature of the melting furnace affecting surrounding the electrical facilities. A safety management scheme on the electrical facility of the melting furnace was proposed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.231-236
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• 2000

In this study, to present the use of the blase furnace slag fly ash derived from a large amount of the industrial products with the early strength reduction of it prevented, the initial strength is measured after a large quantity of fly ash and the required stimulus agent for the high development of the initial strength was added in blast furnace slag cement. As the results, in spite of the much addition of fly ash in blast furnace slag, the long-age strength of blast furnace slag cement was able to be improved by a proper amount of stimulus agent, and was as high as that of ordinary portland cement.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.132-133
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• 2014

In this study, high volume of industrial by-products including blast furnace slag, recycled aggregate powder and incineration ash have been utilized on the slurry of the foamed lightweight concrete. As to decrease the price of the lightweight foam concrete, mortar based slurry and concrete based slurry has been fixed. As the variation of the foam conduction ratio and aggregates, the foam ratio and compressive strength has been tested. Results showed that using recycled aggregates in the slurry showed better effect than using natural aggregates due to the alkali properties of the recycled aggregates could activate the potential hydraulic properties of the blast furnace slag. Consider about the low price of the recycled aggregates, it could be identified that using recycled aggregates in high volume blast furnace slag blended lightweight concrete showed better compressive strength than natural aggregates.